I had my teeth whitened the other day using Zoom Bleaching.
The tech told me that I should not expect a dramatic difference and I was fine with that. My teeth were not horribly yellow to begin with - I just wanted them a little brighter.
Well - after the treatment - which was time consuming and annoying, my teeth look FANTASTIC! They are bright and pearly white. I am THRILLED with the results.
The downside is that my teeth were a little sensitive for the 2 days following - and I had to avoid coffee and tea, berries, red sauces, etc.. for 48 hours. But it feels better now and my teeth look fantastic.
I probably wouldn't recommend bleaching as a way of life... but for a special event where you want your teeth to look their best, I think it worked great. It's like Crest Whitening Strips on steroids!
If anyone wants info on my dentist, FM me!
ETA: I have heard that some people experience have a high degree of sensitivity in their teeth and the treatment may aggravate that condition.. so be wary!